Both amas on my 2015 AI have black marks on them, since both XBars were crushed by the trucking company that delivered it, I'm sure the marks are from handling as well. I've been waiting for replacements XBars so I've had time to try several things; Dawn, alcohol, Simple Green, Citrus cleaner, WD40, 303, Magic Eraser and acetone. Anyone have any suggestions?Mike

Well I finally got around to trying bleach, it didn't work. Now I don't see the marks seeing until I'm washing it down. After a day on the water the only thing on my mind is, when can I go again. Thanks for the suggestions.Mike

The only way I know of to remove scratches or marks like that are with a single edge razor blade, you hold the blade vertical and start scraping back and forth quickly, the plastic comes off like snow, it would take a couple years of continuous scraping to scrape thru the hull. When done you don't have to do anything else, the scraping leaves a very clean nice finish.Hope this helpsBob